fix(runtime-vapor): more accurate fallthrough attr support

[alex-snezhko]

Fix fallthrough attributes in Vapor mode when target component has comments in its template root level

Example
Comp.vue

<template vapor>
  <!--comment-->
  <div>Hello</div>
</template>

App.vue

<script setup vapor>
import Comp from './Comp.vue';
</script>

<template>
  <Comp style="color: red;" />
</template>

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
compiler-dom.global.prod.js	85.2 kB (+325 B)	29.9 kB (+106 B)	26.4 kB (+74 B)
runtime-dom.global.prod.js	108 kB	40.4 kB	36.4 kB
vue.global.prod.js	166 kB	60.4 kB	53.7 kB

Usages

Name	Size	Gzip	Brotli
createApp (CAPI only)	47.9 kB	18.7 kB	17.1 kB
createApp	57 kB	21.9 kB	20 kB
createApp + vaporInteropPlugin	91.3 kB (+124 B)	34.1 kB (+42 B)	30.8 kB (+101 B)
createVaporApp	35 kB (+124 B)	13.4 kB (+42 B)	12.3 kB (+43 B)
createSSRApp	61.3 kB	23.7 kB	21.6 kB
defineCustomElement	63.1 kB	23.8 kB	21.7 kB
overall	72.1 kB	27.3 kB	24.9 kB

[pkg-pr-new]

Open in StackBlitz

@vue/compiler-core

npm i https://pkg.pr.new/@vue/compiler-core@13972

@vue/compiler-dom

npm i https://pkg.pr.new/@vue/compiler-dom@13972

@vue/compiler-sfc

npm i https://pkg.pr.new/@vue/compiler-sfc@13972

@vue/compiler-ssr

npm i https://pkg.pr.new/@vue/compiler-ssr@13972

@vue/compiler-vapor

npm i https://pkg.pr.new/@vue/compiler-vapor@13972

@vue/reactivity

npm i https://pkg.pr.new/@vue/reactivity@13972

@vue/runtime-core

npm i https://pkg.pr.new/@vue/runtime-core@13972

@vue/runtime-dom

npm i https://pkg.pr.new/@vue/runtime-dom@13972

@vue/runtime-vapor

npm i https://pkg.pr.new/@vue/runtime-vapor@13972

@vue/server-renderer

npm i https://pkg.pr.new/@vue/server-renderer@13972

@vue/shared

npm i https://pkg.pr.new/@vue/shared@13972

vue

npm i https://pkg.pr.new/vue@13972

@vue/compat

npm i https://pkg.pr.new/@vue/compat@13972

commit: 11f2c06

[edison1105]

The following scenarios need to be fixed

• Playground - vdom component
• Playground with this PR - vapor component

[alex-snezhko]

@edison1105 updated and edited the PR title!

[edison1105]

Made some tweaks

• Only return singleRoot when the root node contains comment nodes (corresponding to vdom DEV_ROOT_FRAGMENT)
• In vapor mode, there's no need to consider manually written setup scenarios, so setup returning [n0] doesn't need to be considered. If an array is returned, it should contain at least 2 elements.